The highway from Zagreb to Rijeka stretches 68.5 km through a wildlife core area in Gorski kotar (Croatia). It has 43 viaducts
and tunnels, and one specifically constructed (100 m wide) green bridge (Dedin). One quarter of the total highway length consists
of possible crossing structures. At Dedin green bridge, a total of 12,519 crossings have been recorded during 793 different
days of active infrared monitors being in operation, or 15.8 crossings per day. Two monitored tunnel overpasses had 11.2 and
37.0 crossings per day, respectively, whilst 4.3 crossings occurred per day under one monitored viaduct. Of those crossings,
83.2% were by ungulates and 14.6% by large carnivores. Radio-tracked large carnivores, brown bear (
Ursus arctos), grey wolf (
Canis lupus) and Eurasian lynx (
Lynx lynx), expressed strong positive selection for tunnels and viaducts, whilst avoiding small underpasses or bridges. Selection for
the use of Dedin green bridge was equal to its availability. We conclude that this green bridge, constructed as a measure
to mitigate the negative effects of the studied highway, served its purpose acceptably. Territorial and dispersing radio-tracked
large carnivores crossed the highway 41 times, using both sides of the highway as parts of their home ranges. Overall, the
highway in Gorski kotar does not seem to be a barrier. This demonstrates that it is possible to maintain habitat connectivity
during the process of planning the highway route.
Keywords Brown bear - Grey wolf - Eurasian lynx - Green bridge - Habitat continuity
Communicated by H. Kierdorf